Abstract:

A telechelic polymer composition comprising a telechelic polymer having
phenolic hydroxyl groups at both ends and having a weight average
molecular weight in the range of 1,000 to 10,000, and a compound having a
benzoxazine ring structure or a compound having a naphthoxazine ring
structure.

Claims:

1. A telechelic polymer composition comprising a telechelic polymer having
phenolic hydroxyl groups at both ends and having a weight average
molecular weight in the range of 1,000 to 10,000, and a compound having a
benzoxazine ring structure or a compound having a naphthoxazine ring
structure.

2. The telechelic polymer composition according to claim 1, wherein the
telechelic polymer has a polyether ketone structure in the main chain.

3. A telechelic polymer having at least 10% by mole or more of the
phenolic hydroxyl groups at both ends of the polymer capped with a
benzoxazine ring structure or a naphthoxazine ring structure, and having
a weight average molecular weight in the range of 1,000 to 10,000.

4. The telechelic polymer according to claim 3, having a polyether ketone
structure in the main chain.

5. A telechelic polymer composition comprising the telechelic polymer
according to claim 3.

6. A telechelic polymer composition comprising the telechelic polymer
according to claim 4.

[0002]Polybenzoxazine becomes a hard and highly heat resistant resin when
heated. Especially, due to its excellent char yield (rate of
carbonization), the resulting resin is expected to have wide applications
not only as a material for the use in electronic and electric
instruments, but also as a material for the use in the fields of space
and aeronautics as well as in the fields of electronic
telecommunications.

[0003]For example, Japanese Unexamined Patent Publication No. 2003-64180
or literature (Tsutomu Takeichi, Polymer 46 (2005) 12172-12180) discloses
a method of producing a high molecular weight benzoxazine compound in
advance, and cross-linking the compound by heating to produce a cured
product.

[0005]The inventors of the present invention devotedly conducted research,
and as a result, found that a telechelic polymer composition comprising a
telechelic polymer and a compound having a benzoxazine ring structure or
a compound having a naphthoxazine ring structure, and a heat cured
product of telechelic polymer formed by capping the phenolic hydroxyl
groups at both ends of a telechelic polymer with benzoxazine ring
structures, exhibit high breaking elongation, thus completing the present
invention.

[0006]That is, the present invention is as follows.

[0007]1. A telechelic polymer composition comprising a telechelic polymer
having phenolic hydroxyl groups at both ends and having a weight average
molecular weight in the range of 1,000 to 10,000, and a compound having a
benzoxazine ring structure or a compound having a naphthoxazine ring
structure.

[0008]2. The telechelic polymer composition according to above, wherein
the telechelic polymer has a polyether ketone structure in the main
chain.

[0009]3. A telechelic polymer having a weight average molecular weight in
the range of 1,000 to 10,000, the telechelic polymer having at least 10%
by mole or more of the phenolic hydroxyl groups at both ends capped with
a benzoxazine ring structure or a naphthoxazine ring structure.

[0010]4. The telechelic polymer according to 3 above, having a polyether
ketone structure in the main chain.

[0011]5. A telechelic polymer composition comprising the telechelic
polymer according to 3 above.

[0012]6. A telechelic polymer composition comprising the telechelic
polymer according to 4 above.

[0013]The telechelic polymer composition obtained by the present invention
has a low melt viscosity, and thus is easily moldable. Furthermore, a
cured product obtained by curing the composition by heating has excellent
heat resistance and mechanical strength, and thus can be suitably used in
electric and electronic parts, automobile parts, copper clad laminate
boards, printed boards, refractory coatings, matrix resin for composite
materials, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 shows various compounds having the benzoxazine ring structure
or the naphthoxazine ring structure.

[0017]The telechelic polymer composition of the present invention is a
telechelic polymer composition containing a telechelic polymer having
phenolic hydroxyl groups at both ends and having a weight average
molecular weight in the range of 1,000 to 10,000, and a compound having a
benzoxazine ring structure or a compound having a naphthoxazine ring
structure.

[0018]As the polymer used in the main chain of the telechelic polymer
contained in the telechelic polymer of the present invention,
polycarbonate, polysulfone, polyallylate, polyether ketone and the like
can be suitably used from the viewpoint of heat resistance, and
polyallylate and polyether ketone which are easily controllable to
convert the ends to phenol structures, can be more suitably used. As the
telechelic polymer of the present invention, a telechelic polymer having
a polyether ketone structure is particularly suitable.

[0019]The telechelic polymer of the present invention is not particularly
limited, but a telechelic polymer represented by the following formula
(I) or the following formula (II) may be mentioned.

##STR00001##

wherein n represents an integer of 1 or more,

##STR00002##

wherein n represents an integer of 1 or more.

[0020]Furthermore, the telechelic polymer of the present invention is a
telechelic polymer having a weight average molecular weight in the range
of 1,000 to 10,000, the telechelic polymer having at least 10% by mole or
more of the phenolic hydroxyl groups at both ends capped with a
benzoxazine ring structure or a naphthoxazine ring structure.

[0021]The telechelic polymer of the present invention capped with a
benzoxazine ring structure or a naphthoxazine ring structure is not
particularly limited, but for example, as the telechelic polymer capped
with a benzoxazine ring structure, a telechelic polymer selected from the
group represented by the following formula (III) may be mentioned.

##STR00003##

wherein n represents an integer of 1 or more.

[0022]The telechelic polymer composition of the present invention is a
composition containing the telechelic polymer capped with a benzoxazine
ring structure or a naphthoxazine ring structure.

[0023]Method for Producing a Telechelic Polymer

[0024]The method for producing a telechelic polymer of the present
invention is not particularly limited, but hereinafter, there will be
illustrated a method for producing a telechelic polymer represented by
the formula (I), having a polyether ketone structure with the ends
controlled to be converted to phenolic hydroxyl groups.

[0025]Bisphenol is not particularly limited, but a phenol such as
bisphenol A, bisphenol F or bis(4-hydroxyphenyl)sulfone can be used.
According to the present invention, it is preferable to use bisphenol A
from the viewpoint of solubility.

[0026]The aromatic ketone is not particularly limited, but
4,4-difluorobenzophenone, 4,4'-dichlorobenzophenone or the like is
preferred from the viewpoint of reactivity.

[0027]The solvent is not particularly limited as long as it dissolves the
starting material to some extent, and does not inhibit the polymerization
reaction between bisphenol and aromatic ketone, but for example,
N-methylpyrrolidone, dimethylacetamide, dimethylsulfoxide,
dimethylformamide, dioxane and the like may be mentioned.

[0028]Since the above polymerization reaction is accompanied by generation
of acid, it is preferable to use an alkali compound as a neutralizing
agent in order to accelerate the reaction. The alkali compound is not
particularly limited, but sodium carbonate, potassium carbonate or
various amines can be used.

[0029]The reaction temperature and the reaction time are not particularly
limited, but the reaction may be carried out typically at a temperature
of about 100° C. to 180° C. for 1 to 5 hours.

[0030]The telechelic polymer can be precipitated by adding the solution
obtained after the reaction to, for example, a large amount of a poor
solvent such as water, and when the precipitate is separated and dried,
the desired telechelic polymer can be obtained.

[0031]The telechelic polymer of the present invention can be produced,
specifically, according to the following Scheme 1.

[0033]The telechelic polymer capped with a benzoxazine ring structure of
the present invention is a polymer obtained by capping a portion of the
phenolic hydroxyl groups of the telechelic polymer which has phenolic
hydroxyl groups at both ends as described above, with benzoxazine. By
capping a portion of the phenolic hydroxyl groups at both ends with
benzoxazine, the telechelic polymer itself can be imparted with thermal
curability. An exemplary reaction method is presented in the following
Scheme 2.

##STR00005##

[0034]The telechelic polymer capped with a benzoxazine ring structure of
the present invention is not particularly limited, but basically, for
example, the telechelic polymer can be produced by a method of mixing
three components, namely, a telechelic polymer having phenolic hydroxyl
groups at both ends of the polymer chain, an amine and formaldehyde,
adding a solvent as necessary, and heating the mixture while stirring.

[0035]The amine is not particularly limited so long as it is monoamine,
but aniline, methylamine, propylamine or the like can be used.

[0036]Formaldehyde can be used in the form of paraformaldehyde which is a
polymer, or in the form of formalin which is an aqueous solution.

[0037]With regard to the mixing ratio for the telechelic polymer and
amine, it is preferable to add at least 0.05 moles or more of the amine,
relative to 1 mole of the telechelic polymer having phenolic hydroxyl
groups at both ends of the polymer chain.

[0038]The upper limit of the mixing ratio of the amine is not particularly
limited, since any excess amine can be easily eliminated after the
reaction.

[0039]In the case of thermally curing the telechelic polymer capped with a
benzoxazine ring structure of the present invention alone, it is
preferable that at least 10% by mole or more, preferably 50% by mole or
more, of the phenolic hydroxyl groups at the ends of the telechelic
polymer are capped with a benzoxazine ring structure. If the capping by a
benzoxazine ring structure is achieved in less than 10% by mole, when the
telechelic polymer is thermally cured, the strength of the thermally
cured product may be extremely deteriorated.

[0040]The mixing ratio of formaldehyde is not particularly limited, but it
is preferable to incorporate formaldehyde in a mole number which is twice
the mole number of the amine, so as to coincide the mixing ratio with the
stoichiometric ratio.

[0041]The solvent used in the present invention is not particularly
limited, but dioxazine, toluene, chloroform, xylene or the like is
suitably used from the viewpoint of reactivity.

[0042]The reaction temperature and the reaction time are not particularly
limited, but the reaction may be carried out typically at a temperature
of about 50° C. to 110° C. for 2 hours to 24 hours.
According to the present invention, it is particularly preferable to
perform the reaction at 70° C. for 12 hours using chloroform as
the solvent, from the viewpoint of preventing any side reactions during
the reaction.

[0043]The polymer after the reaction can be precipitated by adding the
solution obtained after the reaction to, for example, a large amount of a
poor solvent such as methanol, and when the precipitate is separated and
dried, the desired telechelic polymer capped with a benzoxazine ring
structure can be obtained.

[0044]Production of Telechelic Polymer Composition

[0045]As for the telechelic polymer of the present invention, even if the
telechelic polymer is a telechelic polymer having phenolic hydroxyl
groups at the ends, as represented by the above formula (I) or (II), a
telechelic polymer composition generally capable of thermally curing can
be obtained by separately mixing a compound having a benzoxazine ring
structure (hereinafter, may also be described as benzoxazine compound).

[0046]The benzoxazine compound to be mixed is not particularly limited,
but for example, those benzoxazine compounds generally used as thermally
curable resins, such as 3,4'-dihydro-3-methyl-2H-1,3'-benzoxazine,
3,4'-dihydro-3-phenyl-2H-1,3-benzoxazine and
bis(4-benzyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane, can be used.

[0047]Furthermore, a so-called compound having a naphthoxazine ring
structure (hereinafter, may also be described as naphthoxazine compound)
can also be used. The naphthoxazine compound to be mixed is not
particularly limited, but for example, bis
(4,5-dihydro-5-phenyl-6H-3,5-oxazinyl)naphthalene(15 Na and 26 Na) and
the like may be mentioned.

[0048]These compounds are illustrated in the FIG. 1 in the same order.

[0049]As for the mixing ratio of the telechelic polymer and the
benzoxazine compound or naphthoxazine compound in the telechelic polymer
composition, it is preferable to mix the benzoxazine compound or
naphthoxazine Compound in an amount ranging from 20 parts by weight to
300 parts by weight, more preferably 50 parts by weight to 150 parts by
weight, relative to 100 parts by weight of the telechelic polymer.

[0050]When the benzoxazine compound or naphthoxazine compound is
incorporated in an amount of 300 parts by weight or more, toughness of
the resin obtained after thermal curing may be deteriorated. Also, if the
compound is incorporated in an amount of 20 parts by weight or less,
toughness of the resin obtained after thermal curing may also be
deteriorated, owing to unsatisfactory thermal curing.

[0051]The telechelic polymer composition can be produced by, for example,
mechanically mixing the telechelic polymer (powdered) obtained as
described above, with the benzoxazine compound or naphthoxazine compound
(powdered).

[0052]The method of mixing the telechelic polymer and the benzoxazine
compound or naphthoxazine compound is not particularly limited, but a
method of mixing using a mixing machine such as a super mixer, a stone
mill machine or a pressurized kneader, can be applied.

[0053]Curing by Heating of Telechelic Polymer Composition

[0054]The method for curing the telechelic polymer composition by heating
is not particularly limited, but when the telechelic polymer composition
is charged into a desired mold, and then cured by heating at a
temperature of 180 to 260° C. for 30 minutes to 2 hours, a cured
product can be obtained.

[0055]The telechelic polymer composition of the present invention can be
easily subjected to film formation or the like, and the resulting cured
product has excellent heat resistance and mechanical strength. Therefore,
the composition can be suitably used in electric and electronic parts,
automobile parts, copper clad laminate boards, refractory coatings,
matrix resins for composite materials, and the like.

EXAMPLES

[0056]Hereinafter, the present invention will be described in more detail
with reference to Examples, but the present invention is not intended to
be limited to the Examples described below. In addition, the term percent
means percent by weight in the following.

[0057][Measurement Methods]

[0058]The methods for measuring properties in the present specification
are as follows.

[0059](1) GPC Spectrum

[0060]The measurement was performed using a Waters 440 ultraviolet (UV)
detector manufactured by Waters Corp., and columns connected in series
and packed with styrene gels having a pore size of 1000 nm, 100 nm and 50
nm, respectively, and using THF as the eluent.

[0067]The measurement was performed according to ASTM D638-03, using an
Instron universal tester (Model 5565).

[0068]The specimen form used was Type 5 (width 3.18 mm, length 9,53 mm),
and an average of 5 samples was taken as the measured value.

[0069]The elongation at the time of fracture during the tensile test was
taken as the breaking elongation.

Example 1

[0070](Production of Telechelic Polymer)

[0071]To a round-bottom flask having a capacity of 200 cc equipped with a
Dean-Stark collector, 4.36 g (0.02 moles) of 4,4'-difluorobenzophenone,
6.84 g (0.03 moles) of Bisphenol A, 5.56 g (0.04 moles) of potassium
carbonate, 10 g of toluene, and 50 g of dimethylsulfoxide were added.
While stirring, the temperature of an oil bath was elevated to
170° C., and a reaction was performed continuously for 2 hours
while refluxing the solvent Then, the reaction solution was cooled to
about 80° C.

[0072]Solids were removed from this solution by filtering, and the
filtrate was added dropwise to 1 liter of a 1% aqueous acetic acid
solution under vigorous stirring. Precipitated solids were filtered, and
then washed with methanol. The obtained powder was subjected to vacuum
drying for 24 hours in a vacuum oven heated to 50° C.

[0073]The molecular weight of the polymer was measured by GPC, and as a
result, the number average molecular weight of this polymer was measured
to be approximately 2200 (normalized to the reference of polystyrene).

[0074]An FT-IR spectrum of the resulting telechelic polymer is presented
in FIG. 2

[0075]The peak of the terminal phenolic hydroxyl group is observed in the
region of 3500 to 3300 cm-1. The sharp peak shown near 2965
cm-1 corresponds to the methylene of Bisphenol A. The sharp peak
near 1243 cm-1 corresponds to the aromatic ether.

[0076]The peaks appearing at 1593 cm-1, 1498 cm-1, 833 cm-1
and 557 cm-1 are believed to be the absorption of para-substituted
benzene.

[0077](Production of Telechelic Polymer Composition)

[0078]To 5 g of the telechelic polymer produced in the above, 5 g of a
general-purpose benzoxazine compound,
Bis(4-benzyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (Shikoku Chemical
Corp.) was added, and the mixture was mixed for 5 minutes in a small size
stone mill machine, to produce a telechelic polymer composition.

[0079](Production of Sheet)

[0080]The telechelic polymer composition produced in the above was placed
under a hot press releasably treated and controlled to a temperature of
180° C., and was subjected to curing by heating for 1 hour without
pressurizing. Then, the resultant was cooled.

[0081]The novel telechelic polymer composition was molded into a sheet
having a thickness of 0.1 mm.

[0082]The tensile strength and the breaking strength during the tensile
test of this sheet were measured (Table 1).

[0084]The telechelic polymer produced in Example 1 is further modified.

[0085]10 g (equivalent to 0.005 moles) of the telechelic polymer obtained
in Example 1, a 40% aqueous solution of methylamine (Wako Pure Chemical
Industries, Ltd.) (3.88 g, 0.05 moles), a 37% aqueous solution of
formaldehyde (Wako Pure Chemical Industries, Ltd.) (8.1 g, 0.1 moles),
and 70 g of chloroform were added to a flask having a capacity of 200 cc
equipped with a reflux unit. While stirring, the temperature of an oil
bath was elevated to 80° C., and a reaction was performed
continuously for 12 hours while refluxing the solvent. Then, the reaction
solution was cooled to normal temperature.

[0086]This solution was added dropwise to 1 liter of methanol under
vigorous stirring. Precipitated solids were filtered, and then washed
with methanol. The obtained powder was subjected to vacuum drying for 24
hours in a vacuum oven heated to 40° C.

[0087]A 1H-NMR spectrum of the resulting powder is presented in FIG.
3.

[0088]Two peaks of identical size, which are characteristic to
benzoxazine, are observed at 3.92 ppm and 4.81 ppm ((Ar--CH2--N) and
(O--CH2--N), respectively).

[0089]A peak for the isopropyl of bisphenol (Ar--C--CH3) is observed
at 1.60 ppm, but since the peaks of the isopropyl at the end and of the
isopropyl at the center are not equivalent, two peaks are seen when
observed carefully.

[0090](Production of Sheet)

[0091]The telechelic polymer capped with a benzoxazine ring structure
produced in the above was placed under a hot press releasably treated and
controlled to a temperature of 180° C., and was subjected to
curing by heating for 1 hour without pressurizing. Then, the resultant
was cooled.

[0092]The novel telechelic polymer composition was molded into a sheet
having a thickness of 0.1 mm.

[0093]The tensile strength and the breaking elongation during the tensile
test of this sheet were measured (Table 1).

Comparative Example 1

[0094]A general-purpose benzoxazine compound,
bis(4-benzyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (Shikoku Chemical
Corp.) was placed under a hot press releasably treated and controlled to
a temperature of 190° C., and after heating the compound for 3
minutes to increase the melt viscosity, the compound was subjected to
curing by heating for 1 hour without pressurizing. Then, the resultant
was cooled.

[0095]The benzoxazine compound was molded into a sheet having a thickness
of 0.1 mm.

[0096]The tensile strength and the breaking elongation during the tensile
test of this sheet were measured (Table 1).

[0097]As it is obvious from the above results, the telechelic polymer
composition of the present invention results in a tough resin composition
having a large breaking elongation during tensile test, compared to
conventional resins formed from benzoxazine compounds.